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Background: Ablation of long-standing persistent atrial fibrillation (AF) remains challenging, with a lower success rate than paroxysmal AF. A reliable ablation endpoint has not been demonstrated yet, although AF termination during ablation may be associated with higher long-term maintenance of sinus rhythm (SR)., Objective: The purpose of this study was to determine whether the method of AF termination during ablation predicts mode of recurrence or long-term outcome., Methods: Three hundred six patients with long-standing persistent AF, free of antiarrhythmic drugs (AADs), undergoing a first radiofrequency ablation (pulmonary vein [PV] antrum isolation and complex fractionated atrial electrograms) were prospectively included. Organized atrial tachyarrhythmias (AT) that occurred during AF ablation were targeted. AF termination mode during ablation was studied in relation to other variables (characteristics of arrhythmia recurrence, redo procedures, the use of adenosine/isoproterenol for redo, and comparison of focal versus macroreentrant ATs). Long-term maintenance of SR was assessed during the follow-up., Results: During AF ablation, six of 306 patients converted directly to SR, 172 patients organized into AT (with 38 of them converting in SR with further ablation), and 128 did not organize or terminate and were cardioverted. Two hundred eleven of 306 patients (69%) maintained in long-term SR without AADs after a mean follow-up of 25 +/- 6.9 months, with no statistical difference between the various AF termination modes during ablation. Presence or absence of organization during ablation clearly predicted the predominant mode of recurrence, respectively, AT or AF (P = .022). Among the 74 redo ablation patients, 24 patients (32%) had extra PV triggers revealed by adenosine/isoproterenol. Termination of focal ATs was correlated with higher long-term success rate (24/29, 83%) than termination of macroreentrant ATs (20/35, 57%; P = .026)., Conclusion: AF termination during ablation (conversion to AT or SR) could predict the mode of arrhythmia recurrence (AT vs. AF) but did not impact the long-term SR maintenance after one or two procedures. AT termination with further ablation did not correlate with better long-term outcome, except with focal ATs, for which termination seems critical., (Copyright 2010 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: This prospective multicenter randomized study aimed to compare the efficacy of 3 common ablation methods used for longstanding permanent atrial fibrillation (AF)., Methods: A total of 144 patients with longstanding permanent AF (median duration 28 months) were randomly assigned to circumferential pulmonary vein ablation (CPVA, group 1, n = 47), to pulmonary vein antrum isolation (PVAI, group 2, n = 48) or to a hybrid strategy combining ablation of complex fractionated or rapid atrial electrograms (CFAE) in both atria followed by a pulmonary vein antrum isolation (CFAE + PVAI, group 3, n = 49)., Results: Scarring in the left atrium and structural heart disease/hypertension were present in most patients (65%). After a mean follow-up of 16 months, 11% of patients in group 1, 40% of patients in group 2 and 61% of patients in group 3 were in sinus rhythm after one procedure and with no antiarrhythmic drugs (P < .001). Sinus rhythm maintenance would increase respectively to 28% (group 1), 83% (group 2), and 94% (group 3) after 2 procedures and with antiarrhythmic drugs (AADs, P < .001). The AF terminated during ablation, either by conversion to sinus rhythm or organization into an atrial tachyarrhythmia, in 13% of patients (group 1), 44% (group 2), and 74% (group 3) respectively. CFAE alone, performed as the first step of the ablation in group 3, organized AF in only 1 patient., Conclusion: In this study, the hybrid AF ablation strategy including antrum isolation and CFAE ablation had the highest likelihood of maintaining sinus rhythm in patients with longstanding permanent AF. Electrical isolation of the PVs, although inadequate if performed alone, is relevant to achieve long-term sinus rhythm maintenance after ablation. Bi-atrial CFAE ablation had a minimal impact on AF termination during ablation.

Background: Despite the recent advances in cardiac mapping, ablation of scar-related ventricular tachycardia (VT) still remains a clinical challenge. A detailed electroanatomical map is a prerequisite for accurate localization and ablation of the VT substrate., Objective: The purpose of this study was to evaluate the feasibility and accuracy of integrating the positron emission tomography (PET)/computed tomography (CT) with the electroanatomical map and compare the accuracy of the voltage-based scar with the biological scar., Methods: Patients undergoing radiofrequency ablation (n = 19) for scar-related VT were enrolled. CT angiography and PET scans were performed for all patients. Tomographic and volumetric data from both images were processed and coregistered using internally designed software. That image was segmented in an electrophysiology mapping system and registered to the electroanatomical map. Eight different thresholds were applied on the voltage map to define the scar. The surface areas of the biological and electrical dense scars at different thresholds were measured and compared., Results: The PET/CT image was well integrated with the electroanatomical map with a mean surface registration error of 5.1 +/- 2.1 mm. Of the eight different thresholds defining the scar, the surface area of the scar at a threshold of 0.9 mV (68.6 +/- 49.2 cm(2)) correlated best with the surface area of the PET-based scar (70.4 +/- 49.3 cm(2)) and had the least total area error (4.8 +/- 1.8 cm(2)) compared with the 0.5 threshold (29.7 +/- 23.9 cm(2))., Conclusion: Integrating PET/CT with the electroanatomical map is feasible and accurate. Based on the biological scar, readjustment of the voltage scar threshold to 0.9 mV is suggested. In view of the better accuracy of PET/CT in defining scar, the need for acquiring detailed voltage maps may be obviated.

Background: The efficacy of radiofrequency ablation of atypical atrial flutter (AAFL) remains relatively low. This is probably related to the complex mechanism of this arrhythmia or may be due to an inability to deliver sufficient energy during ablation., Objective: The aim of this study is to assess whether an open-irrigation-tip catheter or an 8-mm-tip catheter is more effective for ablation of AAFL in patients with prior history of cardiac surgery and/or catheter ablation of atrial fibrillation., Methods: Seventy patients with AAFL after cardiac surgery/atrial fibrillation ablation were randomized for ablation with either an open-irrigation-tip catheter (Group 1, n=36) or an 8-mm-tip catheter (Group 2, n=34). Acute success was defined as the termination of AAFL by radiofrequency delivery and noninducibility by programmed pacing at the end of procedure. Patients' postoperative courses were followed up by means of intermittent standard electrocardiogram (ECG), transtelephonic ECG monitoring, and telephone interview. All patients underwent 48-hour Holter monitoring at their 3-, 6-, and 9-month follow-up after ablation., Results: Acute success was achieved in 34 patients (94.4%) in Group 1 and 26 patients (76.5%) in Group 2 (P<.05). As compared with the patients in Group 2, more patients in Group 1 remained in sinus rhythm without antiarrhythmic drugs at 90-day follow-up (22 vs 8, P<.05). After 10 months of follow-up, 91.7% of the patients from Group 1 were free of atrial tachyarrhythmias, whereas only 58.9% of the patients from Group 2 remained in sinus rhythm (P <.05). The fluoroscopy and radiofrequency times were significantly shorter when an open-irrigation-tip ablation catheter was used., Conclusion: In patients with a prior history of cardiac surgery or ablation for atrial fibrillation, an open-irrigation-tip catheter is superior to an 8-mm-tip catheter for radiofrequency ablation of scar-related AAFLs. Patients ablated with an open-irrigation-tip catheter seem to have higher acute success rate with less x-ray exposure and radiofrequency delivery, and have a more favorable long-term outcome with more patients maintaining sinus rhythm without antiarrhythmic drugs.

Background: A persistent left superior vena cava (SVC) can be an arrhythmogenic source in patients with atrial fibrillation (AF) through connections from the coronary sinus (CS) and the left atrium (LA). The left SVC can be electrically isolated. However, little clinical data about the impact of left SVC disconnection on AF outcome are available. We report on six patients with left SVC and recurrent AF., Objectives: The purpose of this study was to assess the impact of left SVC isolation on AF recurrence., Methods: Six patients (4 men and 2 women; age 50 +/- 6.4 years) with symptomatic drug-refractory AF and persistent left SVC presented to our laboratory for treatment. Four of the patients had left SVC isolation only because there was no conduction recovery in the pulmonary veins (PVs) after several previous procedures., Results: Conduction between the left SVC and the CS and LA was documented, as was spontaneous ectopies in three patients that degenerated into AF in one patient. Isolation of the left SVC was successful in all patients. Isolation was relatively easy to perform (10.25 +/- 1.6 minutes), with no complications. After follow-up of 13 +/- 7.4 months, all patients were in sinus rhythm and free from AF without antiarrhythmic drugs., Conclusion: This study stresses the importance of looking for unusual sources of AF in patients presenting for repeat procedures or in those in whom the PVs have been ruled out as a source triggering AF. We present clinical evidence that in patients with AF and left SVC, isolation of the PVs only may not be sufficient to suppress AF. Thus, diagnosis and isolation of the left SVC appears critical to preventing AF recurrence in patients with AF when ablation is considered.